/********************************************************************************
 * Copyright 2009 The Robotics Group, The Maersk Mc-Kinney Moller Institute,
 * Faculty of Engineering, University of Southern Denmark
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ********************************************************************************/

#ifndef RWSIM_UTIL_STATESAMPLER_HPP_
#define RWSIM_UTIL_STATESAMPLER_HPP_

#include <rw/core/Ptr.hpp>

namespace rw { namespace kinematics {
    class State;
}}    // namespace rw::kinematics

namespace rwsim { namespace util {

    /**
     * @brief interface for generating states.
     */
    class StateSampler
    {
      public:
        typedef rw::core::Ptr< StateSampler > Ptr;

        /**
                       @brief Sample a state.

                       If sampling fails, the sampler may return the empty configuration. If
                       empty() is true then the sampler has no more configurations.
                       Otherwise sample() may (or may not) succeed if called a second time.
                    */
        virtual bool sample (rw::kinematics::State& state) = 0;

        /**
           @brief True if the sampler is known to contain no more
           configurations.
        */
        virtual bool empty () const = 0;
    };
}}    // namespace rwsim::util

#endif /* STATESAMPLER_HPP_ */
